Each room is different. Go down to the bottom, kill the creeper and get the launchers. Then pick the weakest room to kill first, then continue with that, collecting guns as you go. The top left room is designed to be killed last. By then you should have more than enough blasters to kill the drones there.

Get the Beacon Upgrade and go down the left side. You can build lots of Reactors and then Tech Domes and NOT have to face any enemies until you have upgraded your guns. Hurry, you need to save the bottom Micro Rift before it is destroyed (about 7 minutes).

Hint for tough rooms: You can fill the "safe area" with Anti-Creeper and then Shields. Drones will NOT target anything they don't have a path to without the Micro Rift. Be careful. If they target something that moves through a Micro Rift they WILL use it to follow their target. Keep building shields until the tough Drones are weakened and/or reduced enought for your (upgraded) Blasters to move in and handle.

Save often and if you lose a Blaster (especially at the beginning) reload and try again.

Unit Control"Left Mouse Button" Select a unit. "Right Mouse Button" or "Space" Cancel current selection. "Q" Toggle the active/inactive state of the selected unit. "A" Toggle the armed/unarmed state of the selected unit."X" Destroy the selected unit. "CTRL-#" Assign a group number to selected units. "SHIFT-#" Recall a group number. "CTRL-0" Remove selected units from any group."F" Toggle formation movement.

Other Shortcuts"R" Press and hold to see through terrain. "I" Toggle display of top Information bar. "Arrow-Up" or "G" Scroll the map up. "Arrow-Down" or "B" Scroll the map down. "P" Pause or resume the game. "F1" Switch from/to windowed mode. "CTRL-C or SHIFT-C" Quick Save. "CTRL-V or SHIFT-V" Quick Load. "Backspace" Take a screen-shot of the entire map.